In a typical wireless communication application, every active receiver and transmitter in range joins the network, although in some applications ID numbers are assigned to transmitter and receiver nodes so that only nodes with allowed ID numbers join the network. Consequentially, in prior art network schemes, the nodes of the network are defined either by range or by prior definition based on pre-assigned ID numbers for the nodes participating.
Systems that access all nodes in range may include unnecessary nodes that use up bandwidth of the network. Bandwidth is an issue in common networks, which do not address wide bandwidth signal acquisition due to monitoring hardware and wireless communication bandwidth limitations. The common commercial communication bands, e.g., Bluetooth and Zigbee, do not support wide bandwidth transmission. Wide bandwidth transmissions are generally only provided by military wireless bands or by expensive commercial civilian bands.
On the other hand, systems relying on node IDs are inflexible and may fail to pick up nodes that appropriately should be in the network due to various reasons, such as a failure to include a particular node ID in the list of nodes, or based on a lack of information that the node should be in the network.
In the specific area of railroad cars, no suitable systems exist for properly monitoring them in real time, particularly in the area of monitoring wear and performing predictive maintenance of the bearings of the railroad cars. Bearing failures of individual railcars are responsible for expensive and potentially disastrous derailments.
A number of trackside systems have been developed for monitoring bearing wear and other aspects of individual railroad car operation and movement of common rolling stock, including wayside monitoring systems such as Hot Box Detector (HBD), Trackside Acoustic Detection System (TADS) and Wheel Impact Load Detector (WILD), in which detectors adjacent the railroad track detects passing railroad cars and derives data from them that may indicate a problem with an individual railroad car. These systems can be said to work adequately for the vast majority of existing rolling stock applications, but, as speed of the passing railcars increases, there is less and less time to detect and react to potential problems, since these systems do not provide continuous real-time data. This could theoretically be improved by increasing the number (and thus decreasing the distance) between wayside monitoring systems, allowing more communication with each railcar, but this involves substantial cost associated with installation and maintenance of the trackside detectors.
As can be seen by the bibliography and references listed below, all of which are herein incorporated by reference, the possibility of onboard monitoring devices has been investigated. However, these earlier efforts or devices did not address:                Ease of use and installation        Long power life or power generation        Onboard data processing yielding OK, Caution or Danger status        Viable communication schemes.        
These attributes are necessary for a feasible, practical and economical end item product.
A substantial problem is that wireless systems of the prior art that perform on-board monitoring require substantial amounts of electrical energy to power them. Due to the duration of use of railway cars, the long distances they cover, and the fact that they do not usually have their own source of electrical energy, these systems are not optimal.
Literature of on-board monitoring of railway cars reveals the following:                RR00-02, US Department of Transportation Federal Railroad Administration, “Developed Wheel and Axle Assembly Monitoring System to Improve Passenger Safety”, www.fra.dot.gov/downlods/Research/rr00-02.pdf, March 2000, incorporated herein by reference.        The Federal Railroad Administration (FRA) sponsored test of two systems. The program was initiated in 1995 and the results published in 2000. (www.fra.dot.gov/downlods/Research/rr00-02.pdf), incorporated herein by reference.        The FRA sponsored a program in 1999 with Science Applications International Corporation (SAIC) as the prime contractor. The resulting publication, J. Donelson III and R. L. Dicus, “Bearing Defect Detection Using On-Board Accelerometer Measurements”, Proceedings of 2002 ASME/IEEE Joint Rail Conference, Washington, D.C., 23-25 Apr. 2002, incorporated herein by reference, discusses advantages of onboard monitoring and the enveloping signal processing method which is widely acclaimed in other publications. Other discussions of the enveloping technique can be found in A. Y. Azovtsev and A. V. Barkov, “Improving The Accuracy Of Rolling Element Bearing Condition Assessment”, www.vibrotek.com/articles/abcvi96/abcvi96.htm, Y. A. Azovtsev, A. V. Barkov and I. A. Yudin, “Automatic Diagnostics And Condition Monitoring Of Rolling Element Bearings Using Enveloping Techniques”, www.vibrotek.com/articles/new94vi/index.htm, A. V. Barkov and N. A. Barkov, “The Artificial Intelligence Systems For Machine Condition Monitoring And Diagnostics By Vibration”, www.vibrotek.com/articles/intelect-englindex.htm, A. V. Barkov, “The Capabilities Of The New Generation Of The Monitoring And Diagnostic Systems”, www.vibrotek.com/articles/metal-e/index.htm, D. Gluzman, “Recognizing Impending Bearing Failure”, Reliability Magazine, June, 2001, Reliability Direct, Sales Technology, Inc., “Field Application Notes, Rolling Element Bearings”, www.reliabilitydirect.com/appnotes/reb.html, and I. Howard, “A Review Of Rolling Element Bearing Vibration, Detection, Diagnosis and Prognosis”, Research Report DSTO-RR-0013, Aeronautical and Maritime Research Laboratory Airframes and Engines Division, Department Of Defense, Defense Science And Technology Organization (DSTO), to mention a few, all of which are incorporated herein by reference.        The FRA web site, US Department of Transportation Federal Railroad Administration, Current Projects, Rolling Stock & Components, On-Board Condition Monitoring System (OBCMS), www.fra.dot.gov/us/content/926, incorporated herein by reference, discusses the On-Board Condition Monitoring System (OBCMS) including a demonstration of data collected in 2004.        Also of possible relevance is K. Bladon, D. Rennison, G. Izbinsky, R. Tracy, T. Bladon, “Predictive Condition Monitoring Of Railway Rolling Stock”, Railway Technical Society Of Australasia, Conference On Railway Engineering, Darwin, 20-23 Jun. 2004, also incorporated herein by reference.        
All of the above demonstrated successful monitoring and bearing diagnostic capability using the available bulky power consuming technologies. It appears, however, that development of onboard monitoring systems was discontinued due to the success of the wayside monitoring systems and the inconveniences (large, power-consuming systems requiring cumbersome installation and logistics) imposed by the available onboard monitoring technology.
There is consequently no system available that adequately provides a suitable system for on-board real-time monitoring of railway car bearings to alert the railroad of potential or imminent bearing failure that may create a very dangerous situation or derailment.